Theoretically expected fraction of BHs in mergers, as a function of the primary BH mass at z ∼ 3.4. The SMBHB abundances are evaluated for two values of the minimum mass ratio (q_min = 0.1, 0.74), both independently of separation: Eq. (5) with Δz = 0.7 (dashed and solid blue lines) and at the GW decay-dominated separation, given by Eq. (6) with a = a_gr (dot-dashed and dotted blue lines). Overplotted as the green-shaded band is the dual AGN fraction measured by JWST. The dashed red line shows the typical BH mass of the JWST sample.